Production of β-fructofuranosidase showing fructose-transferring activity by Penicillium frequentans (P. glabrum)

Microorganisms producing enzymes showing fructose-transferring activities were screened from various samples such as soils, flowers, vegetables and fruits. One fungus isolated from azalea was found to produce β-fructofuranosidase, which shows fructose-transferring activity, when cultivated in media containing sucrose as a carbon source. From its growth and morphological characteristics, this strain was identified as Penicillium frequentans (P. glabrum). The strain utilized sucrose and raffinose but not inulin; sucrose was the best carbon source for the production of the enzyme. When cultivated for 4 d in a medium containing 15% (w/v) sucrose under optimal conditions, the fructose-transferring activity reached a maximum of 5.4 U/ml. Under these conditions, 95% of total enzyme activity was detected in the cell-free extract but not in the culture filtrate.